A foster father who admitted for a second time abusing youngsters in his care, including a young girl with learning difficulties, has been handed a three-year sentence.

Judge Gordon Kerr QC told 66-year-old Brian Jackson, who was already on probation for abusing a girl, that only a jail term would merit the breach of trust he displayed for offending which was committed over a prolonged period.

The Belfast Crown Court judge said that Jackson carried out "multiple offending on vulnerable girls to satisfy his own lust."

The pensioner - who is already on the Sex Offenders Register - was informed that he will serve half of his sentence in prison, with the remaining 18-months spent on supervised licence upon his release.

Jackson - who along with his wife fostered around 50 children during their careers as carers - had been serving a period on probation for previous convictions in relation to four indecent assaults against another young girl, prior to being jailed today.

From Beresford Hill in Dromore, the father of four admitted a total of 13 charges against three children in his care. The abuse of the girls took place over a period spanning from May 1998 to July 2010.

At a previous hearing at Belfast Crown Court, prosecuting barrister Margaret-Ann Dinsmore QC said the Jacksons were approved as foster cares in March 1985, and that they fostered around 50 children.

In October 2012 one of the children they fostered made a complaint against Jackson, claiming he had abused her on several occasions.

Ms Dinsmore said that this victim, who is now aged 29, made the case that she was targeted by her foster father "four or five times a month over a period of two years when she was aged between 12 and 14."

Another of Brian Jackson's victims, who was fostered by the couple when she was aged around six, was removed from their care when she reported that Jackson has stuck his tongue in her mouth.

A third victim, who has learning difficulties, was fostered by the Jacksons when she was aged 12 to 14, and was one of the last children to be placed in their care.

The girl subsequently told her grandmother she had been abused by Jackson on two separate occasions when she was 13. Ms Dinsmore told the court that on one of these occasions, Jackson got her on the floor and abused her "under the guise of playing."

Referring to his victim, Ms Dinsmore said spoke of the "intensity of her vulnerability", given that she has learning difficulties.

Speaking of the breach of trust on Jackson's part, Ms Dinsmore said that one of the victims regarded Jackson as her father as she was fostered by the couple from a young girl up until the age of 18. The barrister said: "The level of bonding and perception of that child towards that man was one in which there was clear, deep-rooted composite trust."

Mr Dinsmore also spoke of "the element of grooming" involved, as well as the impact Jackson's offending had on the girls. She did, however, acknowledge that Jackson's guilty plea had spared the victims the "ordeal of going through a trial."

Defence barrister Charles McCreanor QC told Judge Kerr that Jackson was the subject of a "very intense" probation programme, and that he was making good progress.

He also revealed that his client has some health issues, was now living "very much an isolated, lonely existence" and "lives in shame and remorse."

Passing sentence, Judge Kerr spoke of the impact Jackson's offending has had on his victims, the "very serious breach of trust", and the multiple offences committed over a prolonged period.